Multi-Modulus Prescaler with Improved Noise Performance

摘要

Design techniques for multi-modulus prescaler circuits that minimize the input-to-output delay dependence on the modulus control state or history. The feed-forward signal path inside a multi-modulus prescaler is identified, as well as all feedback paths connected to the feed-forward signal path. In various embodiments, one or more of several techniques may be applied to reduce capacitive load variations and signal coupling due to the modulus control state or history. For at least one component coupled to the feed-forward signal path and having a feedback path, a buffered feedback path may be created separate but parallel to a buffered feed-forward signal path. Double buffers may be added to some feedback paths directly coupled to the feed-forward path so that the forward signal path is not affected by load variations in such feedback paths.

主权项

1. A method for reducing the phase noise of a multi-modulus prescaler electronic circuit, including:
(a) providing a feed-forward signal path for the multi-modulus prescaler electronic circuit; (b)providing at least one feedback path within the multi-modulus prescaler electronic circuit; and (c) buffering each feedback path and the feed-forward path to create a separate but parallel te-a buffered feed-forward signal path and feedback paths.